<!doctype html>
<title>{% block title %}{% endblock %} | My Site</title>
<nav>
  <ul>
    <li><a href="{{ site_url }}/index.html">Index</a></li>
    <li><a href="{{ site_url }}/about.html">About</a></li>
  </ul>
</nav>
{%- set global_variable = 42 %}
<div class="content">
  {% block body %}{% endblock %}
</div>